<template>
	<view class="u-wrap">
		<!-- 状态栏 -->
		<view class="header" :style="{ paddingTop: topHeight + 50 + 'rpx' }">
			<view class="input_left" @click="backurl">
				<!-- <text>分类</text> -->
				<u-icon name="arrow-left" color="#FFF"></u-icon>
			</view>
			<!-- <view class="input-box">
				<input placeholder="搜索"  placeholder-style="color:#c0c0c0;" v-model="keyword" @confirm="inputClick" />
				<view class="icon search"><u-icon name="search"></u-icon></view>
			</view> -->
			<!-- <view class="icon-btn" @click="inputClick"><text>搜索</text></view> -->
		</view>
		<!-- 占位 -->
		<view class="place"></view>
		<view class="u-menu-wrap">
			<scroll-view scroll-y scroll-with-animation class="u-tab-view menu-scroll-view" :scroll-top="scrollTop" :scroll-into-view="itemId">
				<view v-for="(item,index) in categorycat.cat_list" :key="index" class="u-tab-item" :class="[current == index ? 'u-tab-item-active' : '']"
				 @tap.stop="swichMenu(index)">
					<text class="u-line-1">{{item.name}}</text>
				</view>
			</scroll-view>
			<scroll-view :scroll-top="scrollRightTop" scroll-y scroll-with-animation class="right-box" @scroll="rightScroll">
				<view class="page-view">
					<view class="class-item" :id="'item' + index" v-for="(item , index) in categorycat.childlist_list" :key="index">
						<view class="item-title">
							<text>{{item.name}}</text>
						</view>
						<view class="item-container">
							<view class="thumb-box" v-for="(item1, index1) in item.childlist" :key="index1"  @click="goDetail(item1.id)">
								<image class="item-menu-image" :src="item1.icon" mode=""></image>
								<view class="item-menu-name">{{item1.name}}</view>
							</view>
						</view>
					</view>
				</view>
			</scroll-view>
		</view>
	</view>
</template>
<script>
//高德SDK
// import amap from '../../common/SDK/amap-wx.js';
export default {
	data() {
		return {
			topHeight: 0,
			showCategoryIndex: 0,
			headerPosition: 'fixed',
			city: '北京',
			//分类列表
			categorycat:{
				cat_list:[],
				childlist_list:[]
			},
			categoryList: [],
			statusBarHeight: '',
			statusBarHeight2: '',
			page:1,
			cat_id:"",
			keyword:"",
			scrollTop: 0, //tab标题的滚动条位置
			oldScrollTop: 0,
			current: 0, // 预设当前项的值
			menuHeight: 0, // 左边菜单的高度
			menuItemHeight: 0, // 左边菜单item的高度
			itemId: '', // 栏目右边scroll-view用于滚动的id
			menuItemPos: [],
			arr: [],
			scrollRightTop: 0, // 右边栏目scroll-view的滚动条高度
			timer: null, // 定时器
		};
	},
	onHide() {
		this.page =1;
	},
	onReady() {
		// // #ifndef H5
		// this.topHeight = wx.getMenuButtonBoundingClientRect().top;
		// // #endif
	},
	onPageScroll(e) {
		//兼容iOS端下拉时顶部漂移
		if (e.scrollTop >= 0) {
			this.headerPosition = 'fixed';
		} else {
			this.headerPosition = 'absolute';
		}
	},
	mounted() {
		let that = this;
		uni.getSystemInfo({
			success: function(res) {
				that.statusBarHeight = res.statusBarHeight + 'px';
				that.statusBarHeight2 = res.statusBarHeight - 10 + 'px';
			}
		});
	},
	onLoad() {
		this.getlist()
	},
	onShow() {
	},
	//下拉刷新
	onPullDownRefresh() {
		this.categoryList = [];
		this.getlist();
		uni.stopPullDownRefresh();
	},
	//上拉加载
	onReachBottom() {
		// this.showCategoryIndex = this.showCategoryIndex + 1
	},
	methods: {
		// 点击左边的栏目切换
		async swichMenu(index) {
			if(this.arr.length == 0) {
				await this.getMenuItemTop();
			}
			if (index == this.current) return;
			this.scrollRightTop = this.oldScrollTop;
			this.$nextTick(function(){
				this.scrollRightTop = this.arr[index];
				this.current = index;
				this.leftMenuStatus(index);
			})
		},
		// 获取一个目标元素的高度
		getElRect(elClass, dataVal) {
			new Promise((resolve, reject) => {
				const query = uni.createSelectorQuery().in(this);
				query.select('.' + elClass).fields({
					size: true
				}, res => {
					// 如果节点尚未生成，res值为null，循环调用执行
					if (!res) {
						setTimeout(() => {
							this.getElRect(elClass);
						}, 10);
						 clearTimeout();
						return;
					}
					this[dataVal] = res.height;
					resolve();
				}).exec();
			})
		},
		// 观测元素相交状态
		async observer() {
			this.tabbar.map((val, index) => {
				let observer = uni.createIntersectionObserver(this);
				// 检测右边scroll-view的id为itemxx的元素与right-box的相交状态
				// 如果跟.right-box底部相交，就动态设置左边栏目的活动状态
				observer.relativeTo('.right-box', {
					top: 0
				}).observe('#item' + index, res => {
					if (res.intersectionRatio > 0) {
						let id = res.id.substring(4);
						this.leftMenuStatus(id);
					}
				})
			})
		},
		// 设置左边菜单的滚动状态
		async leftMenuStatus(index) {
			// this.current = index;
			// 如果为0，意味着尚未初始化
			if (this.menuHeight == 0 || this.menuItemHeight == 0) {
				await this.getElRect('menu-scroll-view', 'menuHeight');
				await this.getElRect('u-tab-item', 'menuItemHeight');
				return
			}
			// 将菜单活动item垂直居中
			this.scrollTop = index * this.menuItemHeight + this.menuItemHeight / 2 - this.menuHeight / 2;
		},
		// 获取右边菜单每个item到顶部的距离
		getMenuItemTop() {
			new Promise(resolve => {
				let selectorQuery = uni.createSelectorQuery();
				selectorQuery.selectAll('.class-item').boundingClientRect((rects) => {
					// 如果节点尚未生成，rects值为[](因为用selectAll，所以返回的是数组)，循环调用执行
					if(!rects.length) {
						setTimeout(() => {
							this.getMenuItemTop();
						}, 10);
						 clearTimeout();
						return ;
					}
					rects.forEach((rect) => {
						// 这里减去rects[0].top，是因为第一项顶部可能不是贴到导航栏(比如有个搜索框的情况)
						this.arr.push(rect.top - rects[0].top);
						resolve();
					})
				}).exec()
			})
		},
		// 右边菜单滚动
		async rightScroll(e) {
			this.oldScrollTop = e.detail.scrollTop;
			if(this.arr.length == 0) {
				await this.getMenuItemTop();
			}
			if(this.timer) return ;
			if(!this.menuHeight) {
				await this.getElRect('menu-scroll-view', 'menuHeight');
			}
			setTimeout(() => { // 节流
				this.timer = null;
				// scrollHeight为右边菜单垂直中点位置
				let scrollHeight = e.detail.scrollTop + this.menuHeight / 2;
				for (let i = 0; i < this.arr.length; i++) {
					let height1 = this.arr[i];
					let height2 = this.arr[i + 1];
					// 如果不存在height2，意味着数据循环已经到了最后一个，设置左边菜单为最后一项即可
					if (!height2 || scrollHeight >= height1 && scrollHeight < height2) {
						this.leftMenuStatus(i);
						return ;
					}
				}
			}, 10)
			 clearTimeout();
		},
		backurl(){
			uni.navigateBack()
		},
		inputClick(){
			this.page = 1;
			this.cat_id = ''
			this.goodsgetlist()
		},
		goDetail(cat_id){
			uni.navigateTo({
				url: '/mallPage/mall/categoryGoods?cat_id=' + cat_id
			});
		},
		back() {
			uni.navigateBack();
		},
		getlist() {
			this.$Request.get(this.$api.mall.cat).then(res => {
				this.categorycat = res.data;
				this.cat_id = this.categorycat.cat_list[0].cat_id
				// this.goodsgetlist()
			});
		},
		goodsgetlist() {
			let data = {
				page:this.page,
				cat_id:this.cat_id,
				keyword:this.keyword
			}
			this.$Request.get(this.$api.index.goodsList,data).then(res => {
				this.categoryList = res.data.list;
			});
		},
		//消息列表
		toMsg() {
			uni.navigateTo({
				url: '../../msg/msg'
			});
		},
		//分类切换显示
		showCategory(index,cat_id) {
			this.showCategoryIndex = index;
			this.cat_id = cat_id;
			this.keyword = '';
			this.categoryList = []
			this.getlist()
		},
		toCategory(cat_id) {
			// uni.setStorageSync('catName',e.name);
			uni.navigateTo({
				url: '/pages/category/goods-list?cat_id=' + cat_id
			});
		},
		//搜索跳转
		toSearch() {
			uni.navigateTo({
				url: '/pages/index/search'
			});
		}
	}
};
</script>
<style lang="scss" scoped>
	.u-wrap {
		height: calc(100vh);
		/* #ifdef H5 */
		height: calc(100vh - var(--window-top));
		/* #endif */
		display: flex;
		flex-direction: column;
	}
	
	.u-search-box {
		padding: 18rpx 30rpx;
	}
	
	.u-menu-wrap {
		flex: 1;
		display: flex;
		background-color: #262626;
		overflow: hidden;
	}
	
	.u-search-inner {
		background-color: rgb(234, 234, 234);
		border-radius: 100rpx;
		display: flex;
		align-items: center;
		padding: 10rpx 16rpx;
	}
	
	.u-search-text {
		font-size: 26rpx;
		color: $u-tips-color;
		margin-left: 10rpx;
	}
	
	.u-tab-view {
		width: 200rpx;
		height: 100%;
	}
	
	.u-tab-item {
		height: 110rpx;
		background: #262626;
		box-sizing: border-box;
		display: flex;
		align-items: center;
		justify-content: center;
		font-size: 26rpx;
		color: #fff;
		font-weight: 400;
		line-height: 1;
	}
	
	.u-tab-item-active {
		position: relative;
		color: #fff;
		font-size: 30rpx;
		font-weight: 600;
		background: #262626;
	}
	
	.u-tab-item-active::before {
		content: "";
		position: absolute;
		border-left: 4px solid #FFC400;
		height: 32rpx;
		left: 0;
		top: 39rpx;
	}
	
	.u-tab-view {
		height: 100%;
	}
	
	.right-box {
		// background-color: rgb(250, 250, 250);
		background-color: #262626;
	}
	
	.page-view {
		padding: 16rpx;
		background-color: #262626;
		
	}
	
	.class-item {
		margin-bottom: 30rpx;
		background-color: #262626;
		padding: 16rpx;
		border-radius: 8rpx;
	}
	
	.class-item:last-child {
		min-height: 100vh;
	}
	
	.item-title {
		font-size: 26rpx;
		// color: $u-main-color;
		color: #fff;
		font-weight: bold;
	}
	
	.item-menu-name {
		font-weight: normal;
		font-size: 24rpx;
		// color: $u-main-color;
		color: #fff;
	}
	
	.item-container {
		display: flex;
		flex-wrap: wrap;
	}
	
	.thumb-box {
		width: 33.333333%;
		display: flex;
		align-items: center;
		justify-content: center;
		flex-direction: column;
		margin-top: 20rpx;
	}
	
	.item-menu-image {
		width: 120rpx;
		height: 120rpx;
	}
.tabview {
	// margin-top: 16rpx;
}
.tabname {
	color: #fff;
	font-size: 30rpx;
	font-weight: bold;
	margin: 30upx 0;
}
.active {
	width: 60%;
	height: 100rpx;
	background: #b9b9b9;
	border-radius: 50%;
}
.status {
	width: 100%;
	height: 0;
	position: fixed;
	z-index: 10;
	background: #F5514D;
	top: 0;
	/*  #ifdef  APP-PLUS  */
	height: var(--status-bar-height); //覆盖样式
	/*  #endif  */
}

.header {
	width: 100%;
	padding: 25rpx 4%;
	display: flex;
	align-items: center;
	font-size: 46rpx;
	// justify-content: space-between;
	position: fixed;
	top: 0;
	z-index: 2;
	// background: linear-gradient(180deg, #000000 0%, #474747 100%);
	background: #262626;
	.input_left {
		width: 100%;
		height: 40rpx;
		text {
			font-size: 60rpx;
			font-family: PingFang SC;
			font-weight: bold;
			color: #282828;
		}
		margin-right: 10rpx;
	}
	.input-box {
		width: 480rpx;
		height: 54upx;
		background-color: #f5f5f5;
		border-radius: 30upx;
		position: relative;
		display: flex;
		align-items: center;
		.icon {
			display: flex;
			align-items: center;
			position: absolute;
			top: 0;
			left: 20rpx;
			width: 60upx;
			height: 60upx;
			font-size: 34upx;
			color: #c0c0c0;
		}
		input {
			padding-left: 78upx;
			height: 28upx;
			font-size: 28upx;
		}
	}
	.icon-btn {
		width: 100upx;
		height: 54upx;
		background: #F5514D;
		border-radius: 10rpx;
		display: flex;
		justify-content: center;
		align-items: center;
		text {
			font-size: 32rpx;
			font-family: PingFang SC;
			font-weight: 500;
			color: #FFFFFF;
		}
	}
}
.place {
	background-color: #262626;
	height: 180upx;
}
.category-list {
	width: 100%;
	// min-height: 100vh;
	background-color: #fff;
	display: flex;
	.left,
	.right {
		position: absolute;

		top: 186upx;
		/*  #ifdef  APP-PLUS  */
		top: calc(100upx + var(--status-bar-height));
		/*  #endif  */
		bottom: 0upx;
	}
	.left {
		width: 24%;
		left: 0upx;
		background-color: #e7e7e7;
		.row {
			width: 100%;
			height: 90upx;
			display: flex;
			align-items: center;
			.text {
				width: 100%;
				position: relative;
				display: flex;
				justify-content: center;
				font-size: 28rpx;
				font-family: PingFang SC;
				font-weight: bold;
				color: #282828;
				.block {
					position: absolute;
					width: 0upx;
					left: 0;
				}
			}
			&.on {
				height: 90upx;
				background-color: #fff;
				.text {
					font-weight: bold;
					.block {
						width: 10upx;
						height: 100%;
						top: 10%;
						background-color: #cb1d1c;
					}
				}
			}
		}
	}
	.right {
		width: 76%;
		left: 24%;
		.category {
			width: 100%;
			padding: 20upx 3%;
			display: flex;
			flex-wrap: wrap;
			.banner {
				width: 100%;
				height: 24.262vw;
				border-radius: 10upx;
				overflow: hidden;
				box-shadow: 0upx 5upx 20upx rgba(0, 0, 0, 0.3);
				image {
					width: 100%;
					height: 24.262vw;
				}
			}
			.fenlei_list {
				display: flex;
				align-items: center;
				flex-wrap: wrap;
				.fenlei_list_box {
					display: flex;
					flex-direction: column;
					margin-right: 10rpx;
					flex-wrap: wrap;
					margin-bottom: 30rpx;
					.list_box {
						width:160rpx;
						height: 160rpx;
						display: flex;
						justify-content: center;
						align-items: center;
						flex-wrap: wrap;
						background-repeat: no-repeat !important;
						background-size: 100% 100% !important;
						image {
							width: 130rpx;
							height: 130rpx;
						}
					}
					.list_text {
						margin-top: 5upx;
						font-size: 22rpx;
						font-family: PingFang SC;
						font-weight: bold;
						color: #282828;
						display: flex;
						justify-content: center;
						align-items: center;
					}
				}
			}
		}
	}
}
</style>
